Dishonest service

I have the black friday special from 2 years ago and I wanted an option from MTN first before seeking business elsewhere. I have tried for days to get through their customer service on 135 and everytime I get through they drop the call at retentions, I even got a message saying the call centre is closed during the day. I called MTN this morning and I finally managed to get through to their call centre. I asked the lady from retentions if she can give me a deal similar to the one i have and she just says the black friday deals that retention offers is now closed and I must go to another provider so they can match the deal. I cant believe that MTN would actually say that instead of helping a customer first. If MTN customer service was down or busy how are we, as customers will get a deal. It is unfair practice from a provider like MTN and I'm sure there are alot of customers who experienced the same thing.